PX4 PWM Rover

I want to know which is the default PWM frequency of the PX4 for the Rover mode.
I also need to know the thresholds for the neutral position, reverse and normal.
I read a lot of numbers in other topics, but no one is clear.
My idea is to use an arduino to connect from my PX4 to the H bridge to control the DC motor.
I need the maximum value of PWM going forward, the value of PWM for neutral position, and the maximum value of PWM going backwards. So that I can convert this PWM signal to IN1, IN2, and ENABLE for the H bridge.
I want to use the analogRead() of arduino to read the PWM of PX4.
Thank you everyone.